The invention relates to hybrid plasmids, in particular so-called shuttle vectors, which are produced by fusion of E. Coli plasmids and the Streptomycetes plasmids pSG2 (European Patent Application with the Publication No. 66,701), pSVH1 (European Patent Application with the Publication No. 70,522) and pSG5 (to which German Patent Application P 34 12 092.0 with the title "The Streptomycetes plasmid pSG5, a process for obtaining it and its use", which was filed on the same date, relates, and which is characterized by FIG. 1), and which therefore undergo autonomous replication both in E. coli and in Streptomycetes. Furthermore, the shuttle vectors according to the invention contain markers, preferably resistance genes, which permit selection in Streptomycetes and/or E. coli. Hence these shuttle vectors permit the application of tested methods of genetic engineering in E. coli, the transfer back into Streptomycetes and the investigation and utilization of manipulated genes in Streptomycetes. Other aspects and preferred embodiments of the invention are illustrated in detail below.